TERNS. 81 
     
    
   
   
    
     under part: white ,' tail light pearl—gray, the outer feather darker toward the 
     
     end, where the inner web is always darker than the outer; bill dull orange, 
     
     the end third blackish; feet orange. Ad. in winter.—Similar to the above, 
     
     but head white, more or leSs washed with grayish or spotted with black, a 
     
     large black spot on the side of the head inclosing the eye; bill mostly black; 
     
     feet brownish. Ina—Similar to the preceding, but the back and wings more 
     
     or less mottled or washed with light brownish, and the tail much shorter. 
     
     L.,15-00; W.,10‘25; T., 700; Tar., 90; B., 1-50. 
     
    

    
     Range—0f more or less general distribution throughout North America, 
     
     breeding in the east locally from Texas northward through the Mississippi 
     
     Valley to St. Clair Flats and Manitoba—recorded from Lake Mistassini—ap- 
     
     patently not breeding on the Atlantic coast north of Virginia, but wandering 
     
     irregularly to Massachusetts. 
     
    

    
     Washington, rare and irregular T. V. Long Island, rare T. V. in fall. 
     
    

    
     Heat, of seaweed, flags, or weeds on a slight elevation in grassy marshes. 
     
     Eggs, three, very variable, olive-gray, or olive brownish ashy, more rarely 
     
     whitish or buff, heavily marked with chocolate, 1'80 x 1'30. 
     
    
   
   
    
     Dr. Brewer, writing of Mr. Ridgway’s experience with this species 
     
     on Cobb's Island, Virginia, where it was found breeding in numbers, 
     
     says: “It was only less abundant than the Anglia; [= m‘lott'ca]. and 
     
    
   
   
    
     quite as numerous as the himmda, frequenting especially grassy 
     
     marshes, in which it nests. He found it pre-eminently a. marsh Tern. 
     
     It nested in company with, or in close proximity to, colonies of the 
     
     Black-headed Gull. It could be readily distinguished from the Com- 
     
     mon Tern, which it closely resembles when on the wing, by its grating 
     
    
   
   
    
     monotonous note, which very closely resembles one frequently uttered 
     
     by the Loggerhead Shrike” (B. B., and R.). 
     
    
   
   
    
     70- Stem hil‘undo Linn. COMMON TERN; WILsON’s TEEN; SEA 
     
     SWALLow (see Fig. 7). Ad. in, summer.—Whole top of the head black; back 
     
     and wings pearl—gray; inner border of inner web of outer primaries white, 
     
     except at the tip (Fig. 61, c) ; throat white; breast and belly pale pearl—gray ,' 
     
     tail white, the outer webs of the outer feathers gray or pearl-gray; bill red at 
     
     the base, the end third black; feet orange-red. Ad. in winter.-—Similar to 
     
     the above, but front part of the head and under parts white: bill mostly 
     
     black. Ina—Similar to the preceding, but the back more or less washed or 
     
     mottled with light brownish; lesser wing-coverts slaty gray, and tail much 
     
     shorter. L.,15-00; W.,10-25; T., 550; Tar., ‘75; B.,1'40. 
     
    

    
     Remarka—The Common Tom is closely related to Forster’s Tern and also 
     
     to the Arctic Tern. From the former it is to be distinguished by the color of 
     
     the long outer tail-feathers. In the Common Tern the outer web of these 
     
     feathers is always darker than thcinner web; in Forster’s Tern the inner 
     
     web is always darker than the outer one. Adult Common Terns have the 
     
     breast and belly washed with pearl-gray, while in Forster’s Tern these parts 
     
     are pure white. 
     
    

    
     The Common Tern differs from the Arctic Tern in having the bill tipped 
     
    

    
     7